Charles Kennedy has unveiled a five-point pitch aimed at winning the votes of Britain's ethnic minorities.
Kennedy: Laws should reflect Britain's diversity
The Lib Dem leader said his party aimed to reflect the UK's status as a diverse multi-ethnic, multi-faith society.
Although he stressed he wanted to find "better ways" of regulating the asylum system, he attacked those who portrayed immigration as an "unstoppable tide".
Labour wants to introduce tough border controls, while the Tories say new arrivals should have health checks.
In his manifesto, Mr Kennedy said he wanted to create a single equality act to replace the "tangled mess of anti-discrimination laws".
He also proposes to "prioritise international law, democracy and respect for human rights" and he pledged his party would not introduce quotas for asylum seekers.
New Deal money would be used on a "better employment scheme" that recognised some ethnic minority groups faced particular problems entering the jobs market.
"We would ensure that our laws reflect [Britain's] diversity, protecting minorities from victimisation and harassment," Mr Kennedy said.
"For the Liberal Democrats, immigration offers us opportunities to enhance our economy and fill much needed skills gaps."
He added that debate about the "two quite separate issues" of asylum and immigration should never be used to "stoke up fear or racism".
One of the six key Labour pledges unveiled by Tony Blair last week was to introduce ID cards and "strict controls that work to combat asylum abuse and illegal immigration".
The Tories meanwhile have promised an upper limit on the number of people allowed into Britain.
Conservative co-chairman Liam Fox said Lib Dem policies would not wash with the UK's ethnic minorities.
"They are the party that actually wants to abolish faith schools, scrap mandatory life sentences for repeat murderers and rapists, start sex education from the age of seven and increase taxes," he said.
Under Tory plans, non-European Union citizens wanting to work in the UK will also have to undergo tests for Tuberculosis and HIV.
A positive test for TB would mean visa applications being turned down, while HIV would be dealt with case by case.